Determination of Hexanal-an Indicator of Lipid Oxidation by Static Headspace Gas Chromatography (SHS-GC) in Fat-Rich Food Matrices

Lipid oxidation is one of the most detrimental processes in food, occurring during production and storage, and influences food aroma and taste. Analysis of volatile lipid oxidation products provides an insight into the oxidation and some volatiles, such as hexanal can be markers of undergoing oxidation processes. A method for hexanal determination in oil, potato chips, and mayonnaise matrices with high fat content was developed. Water was used as a matrix for comparison of performance of oil, emulsion, or nonhomogenous matrix in hexanal release. Sample weight, mixing with water, equilibrium temperature, and time were determined for each matrix to provide the highest extraction efficiency. The developed method is characterized by detection limits of 0.06, 0.07, and 0.09 mg/kg for rapeseed oil, potato chips, and mayonnaise, respectively, and linearity for all matrices was 0.999 for a range of 0.1-50 (potato chips) or 200 mg/kg (rest of matrices). Repeatability of the method was in a range of 3.11-5.43 % and intermediate precision of 3.59-5.96 % depending on a fat-rich product analyzed. The developed method presents an easy and automated approach to determine hexanal as a marker for lipid oxidation in oils and high fat products.